As is well known in the art, an inductor, such as an inductor used in an RF tunable circuit, shows an inductive value based on its physical characteristics of length, diameter, number of turns and wire thickness. Once those physical characteristic were set, changing the tuned frequency of the circuit required changing a circuit component such as the circuit inductance or capacitance. Changing the inductance requires switching to a new inductor or altering the properties of the inductance in some other way such as changing the magnetic properties of the inductor core by adding a magnetic material into the inductor's core, such as soft iron, or increasing the separation between the individual coils of the inductor. These physical changes were managed by moving a magnetic material into or out of the inductor core, manually separating the coil windings, or by switching inductors into or out of a tuned circuit, upon command or manually, resulting in additional components, or larger size requirements for tuned circuits.
Even where a single value inductor is used, changes in temperature, for example, may alter the physical characteristics of an inductor in a RF tuned circuit, requiring re-calibration, re-tuning, or even rebuilding the circuit to accommodate the ambient temperature around the inductor.
Therefore, there exists a need to resolve these problems with the prior art and to significantly improve the way the value of inductors in tuned circuits may be altered, without the need to add components to the tuned circuits.